COMSOL Forums: transient heat flux and temperature analysishttp://www.comsol.com/community/forums/general/thread/34767/
Most recent forum messagesThu, 14 Feb 2013 12:57:01 +0000COMSOL Forums: transient heat flux and temperature analysishttp://www.comsol.com/shared/images/logos/comsol_logo.gifhttp://www.comsol.com/community/forums/general/thread/34767/
Re: transient heat flux and temperature analysishttp://www.comsol.com/community/forums/general/thread/34767/#p95847
Hi<br />
<br />
you need to define your heat shape via an analytical or a combination of step, rectangle or ramp function (Definitions - Functions, then use the correct (t[1/s]) argument when calling your function in the BC or domain variable field, and set up stepping range values such to cover your transitions and it should go.<br />
<br />
Last: check your solver &quot;stepping&quot; settings and do NOT use automatic, but try intermediate or strict, check the doc<br />
<br />
--<br />
Good luck<br />
IvarThu, 14 Feb 2013 12:57:01 +000034767.1360846621.95847Re: transient heat flux and temperature analysishttp://www.comsol.com/community/forums/general/thread/34767/#p95821
Thank you Sir, <br />
<br />
for your reply.<br />
<br />
The matter is the volumetric heat generation varies with time...for example( the transient is of 0 to 50e-06 seconds)- at 1.26E-06 seconds, it is 4e12 w/m3 and 50e-06 seconds, it is 1e10 w/m3... and for this I want to check total thermal flux and temperature variation as output.<br />
<br />
You are requested to direct me for this and if possible sir, please mention the steps..<br />
<br />
I am deeply re grated for your inconvenience.<br />
<br />
<br />
Regards,<br />
Mihir Thu, 14 Feb 2013 02:44:45 +000034767.1360809885.95821Re: transient heat flux and temperature analysishttp://www.comsol.com/community/forums/general/thread/34767/#p95759
Hi<br />
<br />
as for any other model, you need to start and proceed the same way: geoemtry, materials, physics, BC's then mesh and solve, and final postprocessing.<br />
Now &quot;bounday&quot; setings are required for typically initial and fixed temperatures and sources, but a &quot;volume source&quot; is a domain condition and not really a &quot;Boundary condition&quot;<br />
<br />
Note also that, if you are in any other size than MEMS dimensions (&lt;1mm) then micro-second themperature effects are not really frequent and expected, fromm my knowledge (except perhaps if you are dealing with chemistry and rapid chemical reactions)<br />
<br />
--<br />
Good luck<br />
IvarWed, 13 Feb 2013 12:28:56 +000034767.1360758536.95759transient heat flux and temperature analysishttp://www.comsol.com/community/forums/general/thread/34767/#p95749
Dear all,<br />
I am very new to COMSOL multiphysics.<br />
I am doing a transient thermal analysis on geometry containing ceramic and aluminum blocks.<br />
for the boundary conditions I need to define volumetric heat generation with respect to time, rest of the other boundary conditions like convection and initial temperature are constant.<br />
As a result of this I want to see temperature and total heat flux for a transient having a microseconds scale.<br />
<br />
Please help me....<br />
<br />
appreciate all kind of help<br />
<br />
MihirWed, 13 Feb 2013 07:38:34 +000034767.1360741114.95749